Fluval FX6 High Performance Aquarium Filter, Canister Filter for Aquariums up to 400 Gal.

The Fluval FX line of filters is a real work horse which rarely goes wrong if you do the upkeep on it. I use one on the tank I have my turtle in, and it keeps the water crystal clear, even though the old boy digs a lot an tries everything he can to cloud up the water. If I take it off line for cleaning (which is a breeze) or maintenance, it will get the water clear again within an hour if the turtle has been very active while it was off, and much sooner if he wasn't moving around too much. He's a very active turtle, and a very messy eater, but he's neither active enough nor messy enough to overwhelm the FX-6. I also use an FX-6 on my hillstream tank which requires a lot of flow. It pushes the water through at a very good clip so that the stream has a pretty good current for my hillstream loaches and for my rainbow shiners to run in when they're getting ready to spawn. I have the FX-4 on a 20 gallon tank which is probably just a bit overpopulated, But again, it is a good enough filter that it keeps the water quite clean. With surface skimmers on my tanks, even the water's surface is clear. To clean the filter media, all you need to do is lift the media baskets out, the use the filter's bucket to clean the sponges and reusable media, replace the media which has broken down too much to be reused, or which uses chemical treating, then either empty the old water out and replace it with fresh clean, or keep the old water if it's not too bad (it is almost always too bad). The reason you clean the media in the water the filter bucket has in it is so that you don't loose any of the beneficial bacteria which is growing in it. The FX series of filters have variable flow valves, which is a nice feature, though many filters have that. If you close the valves before opening the lid of the filter, you don't have to worry about draining the hoses, and they will be good to go when you turn the filter back on and open the valves. No priming needed. Everything in this filter is easily repairable if something goes wrong. If something happens which wears out the impeller, it's very easy to take the old impeller out, and drop a new one in. It's also easy to replace all the O-rings when they get old and start to loose their ability to seal the unit. If you're unlucky, you might need to do that once a year, but it's more likely that you'll just need put new lubricant on them. I am mechanically challenged, so if I find it easy to take care of, I'm sure just about anyone will be able to do it. I have had problems with several of the other big brands of filter makers, but I have never had a Fluval FX series filter go south on me. I recommend them to anyone who wants to keep their fish's environment clean and healthy. If I ever start another tank, I'll definitely be buying another Fluval FX.

We bought this canister filter for our aquatic turtle in Dec 2020 and it was the best investment ever!! It's quiet and works non stop cleaning her 100 gal tank! Woke up this morning to her tank looking horribly bad! The water, which is usually clear to clear with a slight green tint to it, was a dark muddy mess and we couldn't even see our 11 inch turtle, Crush! We thought our fantastic filter had conked out, but once we drained the water we could see what had happened... our silly girl had knocked the input tube apart and had caused a big air bubble in the filter, and subsequently the filter dumped a ton of muck back into her tank trying to fix the issue. So we did a cleaning of the tank and hooked the filter back up and everything is running smoothly & quietly just as it should!!! We love this filter... it just needs to be taken apart and cleaned every 6 months, witch we do like clockwork! We had tried other filters from our local pet store before getting the Fluval FX6 and they were all a waste of time and money! I can't recommend the Fluval FX6 enough!

Ive been running the Fluval for about 3 months now, and I am absolutely OBSESSED with its quality. I have a 75 gallon tank with a turtle and pleco (both produce A LOT of waste). Previously I was a die hard Penn Plax Cascade fan for the last 5 years, but my last two had motor failures and they changed their warranty terms finally, so I decided to switch it up. Long ago I wanted a Fluval, but but the price was steep so I settled for less and let me just say it’s the best investment you can make. It’s quiet (don’t know why other reviews say it’s not unless they are keeping their water levels really low), my tank remains crystal clear with my normal monthly maintenance routine, and it is easy to clean and change out my media. The fasteners are really not that complicated and don’t take that long to unlock like other reviews say. The canister itself is designed so that it is air tight and I’ve had no signs of leaking. The outtake is made so you have two options to direct the flow of your water which is helpful if you have a basking platform above half of your tank. Highly recommend.

The Fluval FX series canister filters are top quality. The product has an amazing warranty and help is available if needed. This product is sold globally and contains directions and replacement parts list in multiple languages. It is very easy to set up and install all components. I have 4 fx series filters I have them on every fish tank. I will never go back to a hang on back filter after I started to use canister filters. Im a customer for life.

Amazing filter. Reading through how to use the product feels like it will be a breeze to use. Has my 125gal tank looking amazing. Suction and adjustability is top tier. Was afraid to cut the hoses to size but it makes sense and was really easy to do. I’m hoping I can rig up a system to use the bottom hose attachment with my long hose. Hopefully I don’t make a mess!

I bought an FX5 in 2011. Seven years later it is still running like brand-new. I bought an FX6 in 2013. Five years later . . . .like brand new. I've been keeping fish for more than 25 years. During that time I've used many different types of canister and HOB filters. My main recollection with previous canisters was the rage and frustration of priming them, fitting finicky rubber gaskets, dozens of fussy parts. . . After those experiences, the FX5/6 were such a joy. They're simple to assemble, and they prime immediately. Nothing is perfect, so here are pros and cons to help the prospective buyer: PROS: 1. Huge capacity. Imagine a 4-gallon bucket filled with media, with a powerful motor in the lid. 2. Moves a lot of water, and keeps the tank sparkling. 3. Starts instantly and runs like a dream. 4. Reliable - I've been running an FX5 continuously for 7 years; and an FX6 for 5 years. I've never once had any repair issues or problems of any kind. The only maintenance I do is clean or change the media as needed. CONS (and these would probably be better described as "things to consider before getting one"). 1. Powerful enough to suck up fish. In my 120g, I previously had jewel cichlids. They spawned, and whenever I would clean the filter I would find babies inside. Again, this is not a defect, this is just a cautionary note to be smarter than I was about where you use the filter. I currently have guppies in the 120g. They have hundreds of babies. Again, on any given day I'll find a dozen babies in the filter. (FWIW, you can adjust the flow, although I'd suggest that if you need reduced throughput, you might just get a smaller and cheaper filter). 2. It's heavy and awkward. Hey, it's a 4-gallon-ish bucket filled with water and filter media. It's heavy. As another reviewer noted, I have to heave it out of the cabinet and haul it outside to maintain it. 3. You may need to tinker with the selection and placement of filter media. A Google search will yield multiple hits from people who have suggestions and opinions on the topic. I may still be doing it wrong. From bottom to top I have a water polishing pad, two foam pads, and ceramic tubes. For some reason, the polishing pad gets saturated first, and ends up being the reason for reduced flow, while the others are only somewhat dirty. My tank is moderately planted, and I can go through perhaps 4-5 weeks between filter cleanings/media changes. 4. You'll want a towel when disconnecting the filter from the hoses for cleaning. I have not found a way to keep about half a cup of water from escaping whenever I disconnect. 5. It may take some elbow crease to depress the "buttons" (wrong term) to release the hose from the filter body. You have to depress them and lift the hose off, and sometimes it requires some effort. 6. Expensive. It just is. That's a lot of money to drop on a filter. But I think it's well spent. I imagine you're paying for a powerful and well-built motor. No other piece of aquarium equipment (excluding the tank, of course) has lasted me 7 years - let alone in like-new condition. I feel that I easily have another 7-plus years out of it. Bottom line? I see no need to look for alternative filters for large tanks. I just bought a 300g aquarium, and when it arrives I will be furnishing it with another FX5 or FX6.

I've been using the previous version of this filter since April of 2015 without any issues with it. I have it setup for my 75 gallon which I think is the perfect amount of filtration for a 75 gallon to maybe a 125 gallon before you need to run duals. I have to clean the media only twice a year, so no big deal when I do have to do it & there are several options for media you can use in it. You will want to get the service kit for the motor & replace those bits along with the new gaskets in the kit to replace the old ones. Use a slight amount of silicone grease on the o-rings to help prolong life, but after 5 or 6 years you might hear the bushing in the motor start making noises anyways & that's when you need to get the service kit. I got the optional spray bar for the it & that is a worthy investment too & looks cool if you prefer a smoother outflow across a larger area. It's very quiet too unless the motor's bushing is bad, then it's noisy. The only real noise it makes when in perfect shape is the gurgle of bubbles escaping every 12 hours to purge the air that has built up inside the filter. Really nifty feature. It is a little pricey but it has been a very worthwhile investment for my tank & I haven't had any issues with it for over a decade of continuous running besides it being off for a few power outages & when I clean it out. Your tank & bio-load will be different than everyone else's, so it may take a little while to determine when to clean it, but general rule is when the outflow is really low or the impeller stops due to gunk buildup. Some may have to do it once a month, others maybe once or twice a year as I have to do. This filter has just been a real tank for me in the past 10 years so it gets an A++ from me.

Update- The units motor pulsated and is pulsating and began to die after less than seven months. Contacting Fluval is almost impossible as their hours are only 10 to 4 Monday through Friday and they only offer email customer service. And the email process is seriously slow. No voicemail available and no weekend call hours available. Makes it very difficult for those who work Monday through Friday during the hours of 10 to 4. I plan to look at a different brand. This is THE filter to purchase. I have a 90 gallon tank that had a Aquatop CF400UV which circulates 360 gph and worked well. I was looking for something to handle the load with 5 medium fish (2 black Oscars, black ghost knife fish, false tiger, and a Rafael -all will be transferred to a 150 soon). The unit is whisper quiet, easy to set up, and easy to maintain. It’s been running for 4 weeks now and I replaced the carbon pad per the maintenance schedule. Super easy. The flow is adjustable per Fluval at no less than 50% without any adverse effects to the motor. I began with 75% and then moved to full output. One output faces the surface for oxygen agitation and the other is aimed at the bottom of the glass. Works great. Water is crystal clear! I used the media that came with it except I replaced the bio rings with Seachem Matrix and added pouches of Purigen and Phosguard. Suggestions: To avoid water on the interior bottom of your tank stand, place the canister in a plastic storage tub as sold at big boxes (clear plastic tray 6”high by 24” wide) and place two smaller tubs (shoebox size) on the right and left sides if you have the room. When servicing, this allows me to remove the two valves and lay them in a side tubs and slide the tub with the canister out from under the tank stand. This keeps my stand dry. Second, as noted in another review, Flowtamer makes a spray bar specifically for the FX. Of Course you can make one yourself. Third, it does not come with a UV sterilizer but one can be added as I am considering an in-line unit.

Très bon filtre, utilisé pour 2 tortues d'eau, le bruit est résonnable, l'eau reste clair et très propre, le débit est correcte. Le montage est vraiment facile, tout est expliquer en français et detailler avec des illustrations. Pour le nettoyage, rien de plus simple, on peut brancher un tuyau sur la sortie vidange pour vider le contenu et il peut se remplir avec l'eau de l'aquarium, franchement c'est super pratique. La pompe, toute les 12h chasse l'air contenu dans la pompe, tout est automatique, même l'amorçage ! On le branche et ça démarre. Pour l'instant aucune fuite, tout fonctionne très bien , livrer avec des joints en supplément. C'est peut être un peut cher mais côté pratique et gain de temps et performance, je ne regrette rien.

Fluval FX6 ha risolto i mimei problemi di poca dimensione del filtro nell'acquario. Acqua pulita, cristallina e niente più alghe. Le vecchie stanno sparendo e il fondo non ha più residui. Potente e silenzioso. Comodamente riposto nei vani di un Juwel Rio 450 (o Vision 450). Comodo da pulire. Qualche adattamento da fare nella parte superiore dell'acquario (lo ho preferito a fare fori nel vetro). I tubi possono (devono) essere migliorati come estetica e qualità del tubo da parte del produttore, sono grandi, ma gli attacchi rapidi sono ottimi e dotati dei rubinetti di chiusura e apertura. Nulla che dire ottimo investimento. La pulizia del filtro è facile, finalmente niente bagnato o stracci ovunque. Speriamo duri nel tempo.

Funciona perfectamente, gran potencia sin ruidos apreciables. Una buena compra …

These units are made sturdy very thick plastic buckets with a powerful motor to filter large amounts of water!. I am currently using this on a saltwater tank and it is holding up against the salt after two solid years of running. Also there are complete seal kits that you can buy for maintaining the filters life it even comes with a new impeller and ceramic drive rod assembly and all seals needed. All parts are available and change out easily if broken Fluval though of everything with this filter.

Installed this on a 600L setup and it’s been flawless. Prime it once, plug it in, and it just runs. Flow rate’s strong without blasting the fish, and the multi-stage filtration keeps water crystal clear. Handles heavy bioloads—ideal for cichlids, goldfish, or planted tanks with messy eaters. Maintenance is straightforward: shut-off valves, easy-lift baskets, and a purge valve for draining without lifting the whole unit. I’ve cleaned it out monthly and it’s never clogged or dropped flow. ⚙️ Specs & Features Flow Rate: 3500 L/h Tank Size: Up to 1500L Media Baskets: 6-stage filtration (mechanical, chemical, biological) Footprint: Compact for the power—fits under most cabinets Smart Pump Tech: Auto air purge every 24h to maintain efficiency Drain Valve: Bottom purge for easy water changes 🔇 Noise & Build Runs near silent—just a low hum if you’re close. No vibration, no rattle. Build quality’s solid—thick casing, tight seals, and heavy-duty clamps. Feels like pro-grade kit, not hobby gear. 👍 Pros ✅ Massive flow—handles big tanks with ease ✅ Multi-stage filtration—crystal clear results ✅ Easy maintenance—quick access and purge valve ✅ Quiet operation—ideal for living spaces ✅ Durable build—long-term reliability 👎 Cons ❌ Pricey—but worth it for serious setups ❌ Large footprint—check cabinet space ❌ No media included—buy your own to customise ❌ Heavy when full—drain before moving 🧭 Personal Verdict If you’re running a big tank and want gear that just works, the FX6 is a beast. I’ve used it for months—no leaks, no noise, no stress. It’s not cheap, but it’s built to last and keeps water spotless. Ideal for anyone who wants pro-level filtration without babysitting the kit.